The intrinsic optical property of zona pellucida (ZP), termed as ‘birefringence’, has been widely investigated to predict the developmental potential of a fertilized oocytes, as well as ART treatment outcomes. A recent prospective study published in the journal Fertility and Sterility further substantiates the efficacy of ZP birefringence (ZPB) in predicting the developmental competence of oocytes in the metaphase II stage. Continue Reading

Written by Professor Semra Kahraman

The ability to cryopreserve oocytes is of importance in certain clinical and social situations. However, an effective oocyte cryopreservation programme is yet to be developed. In contrast to unsatisfactory results of slow freezing, vitrification of oocytes has yielded comparable pregnancy rates with fresh oocyte retrieval treatments. However, vitrification has not been applied to immature germinal vesicle (GV)-stage oocytes, which are theoretically more resistant to the cryo-damage. In a recent study, researchers investigated whether immature and in vitro matured human oocytes can be successfully vitrified by comparing oocyte survival rates, fertilization, and embryonic development when oocytes are vitrified before and after in vitro maturation (IVM). Continue Reading